Signaling system



Mar. 13, 1923. 1,448,216

^ R. A. HEISING- SIGNALING SYSTEM original Filed July e, 1918 Patented iifilar. l3,@23.

RAYMOND A. MISING, OF MILLBURN, NEW' JERSEY,

TIE/IC COMPANY. INCORPORATED, YORK.

ma en Marit SIGNALING SYSTEM.

Application led July 6, 1918, Serial II'o. 243,566. Renewed .Tune 1, 1922. Serial No. 565,254;

To all whom t may. concern.'

Be it known that I, RAYMOND A. HnIsING, a citizen of the United States, residing at Millburn, in the county of Essex and Statev of New Jersey, have invented certain new and useful Improvementsfin' Signaling Systems,.of which the following is a full, clear, concise, and exact. description.

This invention relates 'to signaling systems, and more particularly to signaling systems of the type in which high frequency oscillations are modulated in acc'ordance with signals.

Au object of the. invention is to provide a modulating and amplifying arrangement of the vacuum tube type in which the number of necessary current sources may be small.

Another object of the-invention is to provide means to enable vacuum tubes arranged Yin cascade to be supplied from common sources ofelectrical energy.

A further object of the invention is to provide a circuit connection for a vacuum tube modulator and vacuum tube amplifier .which will permit the use of common sources of energy for filament heating, space current and impedance controlling purposes.

Still other features of the invention relate to certaincombinations and arrangements of circuits hereinafter described and particularly pointed out in the claims, the advantages of which will he apparent to those skilled in the art. y

In the drawing, lWhich represents diagrammatically one arrangement of circuits according to this invention, a source 1. of high frequency oscillations is illustrated 1n circuit with primary winding 2 of transformer 3 which has a secondary winding 4.'

Microphone 5, Which isl merely representativeof'any form of signal transmitter or of an incoming signal transmitting line, is in circuit with a source of energy 6 and Vprimary Wi'nding 7 of transformer 8, the secondary Winding 9 of which is in series with Winding 4.

A' modulator 10, comprising a'. highly evacuated electron discharge tube having a 'Y hot filament cathode 11, a plate electrode or anode 12, and a grid or impedance-varying element 13, has an input circult connecting its grid and filament including windings'4 and'9 and source 14, which serves to maintain grid 13 at any desired normal negative potential with respect tocathode 11.- Shunted around Winding) are a variable capacity element 15, which serves as a path for high frequency oscillations, and a high resistance element 16, LWhich serves to stabilize the impedance reaction of the secondary circuit ofthe transformer unon its primary over the range of voice frequencies, so as'to prevent distortion. A capacity element 17 may be -employed as a high frequency path-shunting the source 14, particularly where the source must-be located at a considerable distance from the tube of modulator 10 and may have leads of considerable'length subjected to various `inductive and reactive disturbancesn. The output circuit of modulator 10 includes a source 18 of.space current and a tuned loop circuit 19 comprising Vvariable capacity 20, an inductance 21 and an additional inductance element 22 cut inl or out'of circuit by switch 23.

A high resistance 24 having one terminal connected to the plate 12 through a capacity element 25 and its other terminal connected by variable tap 26 to source 14, serves as an Y input circuit foran amplifying device` 27 upon the input terminals of which -it impresses the high frequency variations in elecwhich may be tromotive. force occurring across the output circuit of modulator '10. Amplifier 27 preferably comprises a highly evacuated electron discharge device having a hot filament cathV ode 28, a plate or anode 29 and a id or impedance-varying element 30. F' ments 11 and 28 are heatedv by a common current source 31.

rlhe output circuit of amplifier 27 includes a variable primary Winding 32 coupled to a variable seconda winding 33 which is connected to line 34 y a variable shunt capacity 35 and a varlable series resistance 36,

thus enabling circuit 33, 35, 36 to be tuned flatly to the modulated high frequency cu'rrent to be transmitted. VCapacity elements 37, 38 and39 are provided to serve as high frequency paths for the reason set forth in connection with the description of capacity element 17.

vThe operationof the system may now -be readilyv understood. High frequency Oscil' lations impressed by the primary Winding of transformer 3 upon the input circuit of modulator 10 are modulated in accordance with signal variations impressed upon the sec-1 ondarv of transformer 8. The windings-of trans ormer 3 have' loirmutual reactance,

and. since the secondary of transformer 8 is shunted by high frequency `path 15, the transformers may be made to have little or no direct action as modulating devices. The

Adistributed capacity of the secondary wind-v .will have superposed upon its normal space current amplified variations of speech frequency and the modulated carrier frequency. l

Circuit19 is tuned. to the carrierfrequency and accordingly Aoffers a high impedance to that component while offering a low impedance to speech frequency variations, the effect of the low impedance path being to increase the modulating efficiency of the modulator. 'llhe modulated carrier variations impressed across the terminals of resistance 24 and consequently upon the input circuit of amplifier 27 are, after amplification, impressed by the output circuit of amplifier 27 upon line 34.

lt will be apparent to those skilled in the art that this invention maybe applied to other'systems of signaling as well as to telephony and to guided carrier Wave systems.4

lt is'to be understood that the specific signaling system herein shown and described is merely illustrative of one form in which this invention may be embodied, and that the relative arrangement and location of elements may be materiallyvaried from that set forth.

What is' claimedis:

1. ln combination, two electron discharge devices each having a cathode and input and output circuits connected thereto, common -means for rendering said cat-bodes active, common sources of electromotive force 1n said input and output circuits, and an element of high impedance forming part of the output circuit alternating current path of the first of said devices and also forming part of the input circuit alternating current path of the second of said devices whereby energy variations in the output circuit of the first of said devices are impressed-upon the input circuit of the second of said deviges.

2. A plurality of electron discharge devices each having a'cathode, anv anode anda control element, common means for heating said cathodes and for supplying electron discharge currents in said devices, a vcommon source of potential between said cathodes and their respective control elements and a path of high impedance to currents of the frequencies which it is desired to transmit but of lower impedance for currents of materially differing frequencies common to the cathode anode circuit of one'of the devices and the cathode control element circuit of another of said devices whereby said electron discharge-devices are connected to operate in tandem.

3. lhe combination of` two electron discharge devices each having a cathode, an

anode and an impedance control element,v

common means for maintaining said cathodes 1n electron emlttlng condition, common means for supplylngelectron discharge -current for said devices, a common source of potential difference between said cathodes and their respective cont-rol elements, and an element of high resistance common to the cathode anode circuit of one of said devicesand the cathode control element circuit of the other'of said electron discharge -devices whereby the first device may operate to vary the impedance ofthe second device.

4. The combination of a plurality of vacuum tube discharge devices arranged in tandem, said devices each having a hot filament cathode, an anode and an limpedance varying element, a common'source of heat-j ing current for said filaments, a` common source of space current for said discharge devices, common means for determining the normal potential of each Vimpedance varying element with respect to its associated cath-l ode, and a closed loop circuit tuned approximately to the mean frequency of the currents to be transmitted common to a cathode anode path of one of said devices` and a cathode impedance element path of another of said devices.

5. ln combination, a vacuum tube modulator and a vacuum tube amplifier each having a hot cathode and input and output circuits connected thereto, common means for heating said cathodes and a common source of electromotive force for said outputand said input circuits-*and means connecting said modulatorl and amplifier in tandem.

6. lln combination,` a modulator and an amplifier each comprising a highly evacuated container having a hot filament cathode, an anode and a control electrode, a common source of space current, and a common source-of input circuit potential 4for said modulator and amplifier.

l7. A modulator having an input circuit and an output circuit, means-.connected to said input circuit to impresscarrier 'Waves and modulating waves thereupon, and `a path including a loop tuned to said carrier frequency shunted vacross said output circui 8. A modulator having an input circuit 'Y and an Amitpnt circuit, a source of carrier Waves, means to impress carrier Waves from said source together with modulating Waves;

upon said input circuit, a shunt circuit connected across said output circuit including inductance and capacit-y, said shunt circuit being of relatively lou7 impedance to one of said waves while being of high impedance to the otherl of said waves.

9. A modulator having an input circuit and an output circuit` a source of carrier waves, means to impress carrier waves from said source together with modulating Waves upon said input circuit, and a path including capacity and inductance shunted across said output circuit and tuned to the frequency of one of said Waves.

10. A modulator having an input circuit and an output circuit, means to impress carrier waves and modulating Waves upon said input circuit` and means connected in shunt to said output circuit including a loop tuned to the frequency of one of said Waves.

l1. A modulator having an input circuit and an output circuit, a source of carrier waves, means to impress carrier Waves from said source together with modulating Waves upon said input circuit, and means con? nected in shunt to saidA output circuit inc'luding inductance and capacity, said means being of relatively low impedance to said modulating Waves while being of high impedance to carrier waves. 4

In witness whereof, I hereunto subscribe my name this lst day of July A. D., 1918.

RAYMoNn A.. i-rnrsruu. 

